A small pavilion on the Royal Avenue Gardens contains a working Newcomen atmospheric steam engine, a monument to Dartmouth's most significant contribution to industrial history. The engine on display is an early 18th century machine, demonstrating the basic principle that Newcomen developed: steam admitted to a cylinder, then cooled with water, creating a partial vacuum that allowed atmospheric pressure to push the piston down. The result was a machine that could pump water from deep mines and ran collieries across Britain.
The engine is demonstrated periodically through the season. Even when static, the sheer weight and slow mechanical elegance of the thing is worth a few minutes of your time. A plaque beside the pavilion explains Newcomen's life and the engine's history. The Royal Avenue Gardens around it are pleasant for a sit and a view of the harbour.